In today's point-to-point communications, wireless communication systems may provide some advantages over conventional systems. The communication systems provide efficient allocation of limited communication resources, for example, radio frequency (RF) channels, to a large number of subscribers that use the communication devices, such as mobile or portable radios, for purposes of various communication services. Additionally, many system features, such as channel privacy, user identification, etc., can be incorporated into such systems.
In a wireless communication system, a plurality of communication devices communicate voice and data messages via one or more base stations that provide the air interface and radio link to the communication devices. A communication resource controller is responsible for allocation of the RF channels and other system resources. Generally, the resource controller controls the type of information transmitted to the communication devices. For example, control messages may be communicated over control channels, and voice and data messages may be communicated over voice or data (also known as traffic) channels. The resource controller, upon reception of an inbound channel request from one of the communication devices or when the communication device is being called, allocates the available resources to the requesting communication device.
In some communication system, such as trunked systems among others, the availability of system resources impacts access latency to the communication services. That is, when the communication resources are fully utilized, the subsequent communication devices that request service access are placed in queue until the system resources become available again. It is known to provide service access based on service priority associated with various subscribers. For example, subscribers with a higher service priority are advanced through the queue faster than subscribers with lower service priority.
In order to provide reliable and uninterrupted communication service, some system operators provide a backup communication infrastructure. Under this arrangement, when a main system component goes out of service, a backup system component provides uninterrupted backup communication service. Generally, such backup service is provided to the entire fleets or groups of communication devices, irrespective of the service priority associated with the subscribers. In order to provide the backup service to all of the communication devices, the existing infrastructures use the exact replica of the main components for the backup components. Replicating exactly the main and backup system components throughout the system, however, leads to a very costly infrastructure in which some subscribers may be reluctant to pay for higher service fees, specially those subscribers that require the lower priority services.
Accordingly, there exists a need to provide cost-effective backup communication infrastructure in view of the service requirements of the subscribers.